|
|
 |
 |
Home |
|
|
 |
 |
|
|
|
Cross Hairs on History
The Mystery Machine By Wanda Vivequin Actually, it’s the SUMLOCK COMPTOMETER, a not-so-distant relative of what we now know as a calculator. For people over the age of 50 involved in the world of accounting and business, the name may well remind them of the cavernous rooms full of comptometer operators busily adding and subtracting great rows of numbers. There were even comptometer schools where operators were trained to use the machines. Comptometers became obsolete as the age of microprocessors forged ahead, but they remind us of the days before calculators could fit onto the face of a watch. It was encouraging to hear from current Electrical and Computer Engineering students at the U of A that the comptometer has features that made it a far more reliable adding machine than modern-day calculators and computers. The students had decided to dismantle and repair one of the U of A’s comptometers, which had been suffering from one or two mechanical problems. In the process of disemboweling its moving parts, they discovered things that both impressed and inspired them. “Some interesting features include a manual lock to prevent negative numbers,” says Travis Martin, a fifth-year Engineering Physics student. This means when the zero/reset lever is depressed, it locks the subtraction mechanism. It is not possible to do, for example, zero minus nine equals negative nine. “Another interesting feature is the ability to depress multiple keys, which you cannot do with a modern calculator, limit[ing] the speed of the user,” he says. “This feature certainly impresses me in that, in today’s age of computers, simple issues such as this are often missed in the digital world and create horrid user errors and program crashes from careless programmers.” The comptometer was invented by American Dorr Eugene Felt and was eventually patented in 1887. It was the first successful key-driven adding and calculating machine. Key-driven means that numbers are added to the total just by pressing the keys; no other action is required. At the age of 22, Felt, then working in a machining shop, decided to apply a technology used in planing machines to control the depth of a cut to a calculating machine. He began working on the first rough model of the comptometer over the Thanksgiving holiday in 1884. His first obstacle was to find a box of the right size. He eventually settled on a macaroni box. In his own account of the construction, Felt explained how he used what he could to design the world’s first key-driven adding machine: “For keys, I procured some meat skewers from the butcher around the corner, and some staples from a hardware store for the key guides, and an assortment of elastics to be used for springs. “I soon discovered there were some parts which would require better tools than I had at hand for that purpose, and when night came, I found that the model I had expected to construct in a day was a long way to be complete or in working order.” Just over a year later, after many refinements, Felt finished his working model. The “macaroni box,” as it was always referred to, now resides in the Smithsonian. Word about Felt’s new adding machine got out, inspiring investors. By 1888, the first serious manufacturing and sales of the comptometer was underway. The comptometer was manufactured by Felt and Tarrant Manufacturing Company of Over the years, the machine evolved in size, materials used, and the complexity of calculations that could be carried out. Its basic function is addition. One column of keys is assigned for each decade. When a key is pressed, that number is added to that decade and will carry to the next highest decade if applicable. Comptometers revolutionized the way lists were added. Operators were specially trained to enter all numbers in parallel at the same time. In contrast, a modern calculator only has 10 digit keys—the digits of each number can be entered only one at a time. Multiplication, subtraction, and division were also possible, although somewhat more complicated. Although Felt died in 1930, the comptometer was used extensively until the 1970s. Computers and calculators gradually took over, although many operators continue to insist that comptometers were much quicker. On several websites, they reminisce about the good old days (just Google “comptometer” and see for yourself). Meanwhile, back at the U of A, the students of the Electrical Engineering Club eventually managed to fix the comptometer’s broken bits. The experience gave Martin a whole new perspective on technology. “Concentrating on the mechanical devices encourages the view, at least for me, that the children of the digital era have grown up lazy. They don’t build them like they used to!”
EDITOR’S NOTE: Interested in exploring the intricacies of the comptometer for yourself? Do you have an interesting artifact that would inspire a future story? Please contact Sherrell Steele at 780.492.4514. Wanda Vivequin is an Edmonton-based journalist and is far too young to remember the comptometer.
|
|
|
|
Fall 2005
|
|
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
|
|
|
 |
 |
|
|
|
|
||||
|
||||
